Magnetorheological fluid

Abstract

A magnetorheological fluid utilizing properties of thixotropic agents and having well-balanced sedimentation properties includes: a magnetic material; a medium to allow the magnetic material to be dispersed therein; and at least one dispersant selected from sepiolite and smectite or a dispersant including sepiolite and bentonite.

What is claimed is: 
     
         1 . A magnetorheological fluid comprising:
 a magnetic material;   a medium to allow the magnetic material to be dispersed therein; and   at least one dispersant selected from sepiolite and smectite.   
     
     
         2 . The magnetorheological fluid according to  claim 1 , wherein, in the magnetorheological fluid, a concentration of the magnetic material is 25 wt % to 75 wt %, a concentration of the medium is 25 wt % to 75 wt %, and a concentration of the dispersant is 0.5 wt % to 6 wt %. 
     
     
         3 . The magnetorheological fluid according to  claim 1 , further comprising a reinforcing agent. 
     
     
         4 . The magnetorheological fluid according to  claim 3 , wherein the reinforcing agent is selected from polyhydroxycarboxylic acid derivatives including polyhydroxycarboxylic acid amides or polyhydroxycarboxylic acid esters. 
     
     
         5 . The magnetorheological fluid according to  claim 3 , wherein a concentration of the reinforcing agent in the magnetorheological fluid is 0.025 wt % to 18 wt %. 
     
     
         6 . A magnetorheological fluid comprising:
 a magnetic material;   a medium to allow the magnetic material to be dispersed therein; and   a dispersant comprising sepiolite and bentonite.   
     
     
         7 . The magnetorheological fluid according to  claim 6 , wherein, in the magnetorheological fluid, a concentration of the magnetic material is 25 wt % to 75 wt %, a concentration of the medium is 25 wt % to 75 wt %, and a concentration of the dispersant is 0.5 wt % to 6 wt %. 
     
     
         8 . The magnetorheological fluid according to  claim 6 , further comprising a reinforcing agent. 
     
     
         9 . The magnetorheological fluid according to  claim 8 , wherein the reinforcing agent is selected from polyhydroxycarboxylic acid derivatives including polyhydroxycarboxylic acid amides or polyhydroxycarboxylic acid esters. 
     
     
         10 . The magnetorheological fluid according to  claim 8 , wherein a concentration of the reinforcing agent in the magnetorheological fluid is 0.025 wt % to 18 wt %.